converse



(No Model.)

B. G. CONVERSE.

' TUBING.

No 399,244. Patented Mar. 12, 1889-.

UNITED STATES PATENT @rruem EDMUND (p (,ONYERHE, ()l NEW YURK, N. Y.

TUBING.

SPECIFICATION forming part of Letters Patent No. 399,244, dated March 12, 1889.

Application filed Octoher 22, 1888.

T0 ((ZZ 112710111 it may concern:

Be it known that I, EDMUND toxvunsn, a resident of New'Yorlt, in the county of New York and State of New York, have invented a new and. useful Improvement in Tubing; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to wrought-ironand steel tubing, its object being to provide such a tube suitable for pneumatic and stea1n-boiler purposes, as well as for hand-rails, fencing, hose, and awning-poles, and otheruses where a polished tube is required.

The pnenmaiie tubes new in use are gent-n ally made of brass or copper, whieh elass of tubing is found especially a 'iplieafble, on aeeount of its smooth surlaee, lightness, and non-corrosive properties. Iron or steel tubing, though less expensive than the lnass or eopper tubing, eould not, lmwever, be employed for the purpose, beeause its interior surface was not suii'ieiently smooth, and it was liable to rust or corrode. Its weight also was objectionable, as the ordinary tube could not be welded of plates or sheets sul'lieientl v light for the purpose. ()bjeetion has also been found to iron or steel tubingfor steam-boilers, on account olt its liability to rust or corrode from the ael ion of the oxidizing-waters, and the rapid inerusting thereof with lime or other deposits from the water.

The objeeis of my invention are to provide a wrought-iron or steel tube in which these objections are overeome, and to adapt sueh tubing for uses lorwhieh it has not heretofore been considered applicable.

To these ends my in veution eonsisis g'en-- orally stated, in a driiiwn-iri'm or soft tubing having a soft metal or alloy ei'unpressed into and l'orming a eomposite a llo; with the moleeules ol' the tube on the interior and exterior surtaees thereof, it being found that such a tube having such a finish to it will prevent (-orrosion on aeeount ot' the eomposite alloy formed between the soft-metal routing and the inoleeules of the iron, while at the same time a tube is n-ovided having the interior and exterior surfaces thereof smooth and polished, and the tube formed is light in weight and has all the requisites for pneumatic purposes, while the surface-finish prevents rusting or inerustat-ion, so rendering it specially Serial No. 283,761. lNo model) applieahle for use in steam boilers or eondensers.

To enable others sk lled in the art, to make and use my invention, 1 will deseribethe same more fully, referring to the aeoompanying drawings, in whieh- Figure 1 a view of the ordinarywroughtiron or steel tube. big. 2 is a view of said tube when coated, and Fig. L3 is a view of the tinislunltube l'u forming my improved tubing I emplo a suitable (real ing'qmt for holding the molten metal or alloy, and a suitable drawbeneh in which both the inner and outer surl'aees of thetube can be drawn, sueh as through a soilable die with an interior mandrel, or between eoneave rolls and sueh mandrel. For the purpose oi mating the tubing lemploy a metal \Yllltdl will alloy with the iron or steel body of the tube at a comparatively low heat, and will also adhere thereto under the drawing operation, it being therefore neeessaiwto employ a soft metal or alloy, and one which melts at such a icanperaiure as not lo injure the iron or steel body of the tube. l tiud. that lead or tin, or alloys of lead and tin, orlead, lin, and ani in1ony,orlead, tin, and bismuth, or tin and bismuth are well adapted for the purposes. [have substantially found that the metals best suited for coating the tube are lead and its alloys, the alloys formed with lead gem-rally alloying with the iron or steel bodyot' thei-ubing', and being su'llieiently sell to withstand the severe drawing operai ion wilhout flaking or peeling olt', and to enter into the surface-pores of the iron or steel body as it is eh'ingaied, and by forming the eomposite allo therewith proteet the metal thermi.

In forming my improved tubinglg'enerally take wroughtiron or soil-steel tubing, preferring sol't beenuse of its greater capability of elongation,and in making alight tube for pneumatic purposes I generally eniploy tor the smaller sizes-sueh as from two to three inches in diameler-,a tube of about twelve gage, this being the lightest gage of wroughtiron or steel tubing which ean be eonveuientlv and successfullyniade. l' first cleanse the tube to remove therefrom an v seale or otherimpurities, and then wash the tube to remove acid or like materials used in cleansing the same,

the tube being then in proper condition to receive the soft metal or alloy. 1 then dip the cleansed iron tube in a solution of chloride of Zinc or chloride of tiu,whic.h will prepare the iron or make a solder for the adhesion or alloying of the soft metal or alloy with the surface of the iron body, these steps in the treatment, however, being carried on in whatever way is considered proper for coating the tube with the particular metal or alloy. The tube is then dipped within the molten metal or alloy with which it is to be coated-such as an alloy of lead, tin, and antimonyand in dipping care is takci'l that the interior surface of the tube, as well as the exterior surface thereof, is properly coated, the soft metal or alloy forming an alloy with the body of the' tube and preparing it for the next step in its manufacture. The tube so coated is then taken to the draw-bench, and it is drawn thereon by any suitable mechanism which acts to draw both the inner and outer surfaces of the tube, and the tube is subjected to this drawing operation until it is considerably elongated, being passed between the drawingdies or between the drawing-rolls and drawn over the inner mandrel a sufficient number of times to increase its length from one-fourth to one-half, the die or rolls and the mandrel employed being changed as it is found necessary to complete the drawing operation. The soft metal or alloy coating the exterior and interior surfaces of the tube is by this operation forced into the surfacepores thereof, it being found that by the great pressure and friction applied to the surfaces of the soft metal or alloy as the molecules of the iron are moved under the drawing operation a greater afiinity of the soft metal or alloy to the molecules of the iron is created and the "metal or alloy united with such molecules, the coated metal being thus carried into and caused to penetrate the body of the tube and forming a composite alloy therewith, the composite formed becoming neutral to oxidation or corrosion. The composite surfaces formed on the tube are dense, smooth, and highly polished. At the same time all the imperfections in the body of the tube are filled with the soft metal, and therefore a perfect surface-finish to both the interior and exterior surfaces of the tube is obtained by the elongation of the tube in the drawing operation. I also obtain a tube which is much thinner and lighter in proportion to its length, the tube being generally reduced from,-say, twelvegange to between eighteen and twenty-four gage, and being suliiciently light for all pneumatic purposes. If desired, where the tube is reduced to a very thin gage, it can be redipped in the coating metal, this redipping acting to anneal the body of the tube, so as to prepare it for the further reduction and elongation by the drawing operation, and providing the soft metal or alloy for uniting with any other molecules of the iron which might be brought to the surface during such second drawing of the tube and which might not have been previously alloyed with the soft metal, as Well as to increase the proportion of the soft metal in the composite alloy formed with the iron. The soft metal or alloy thus acts to incorpol rate itself with the iron or steel body of the l tube and imparts thereto the non-corrosive quality of such soft metal or alloy, and where the tube is reduced to a very thin gage the soft metal or alloy practically penetrates through the body of the tube. here the tube is coated on the interior and exterior surfaces and subsequently drawn to form the l composite alloy on both its interior and eX- terior surfaces, as above referred to, it is found in practice that a much greater elonga tion of the tube can be obtained at each operation without affecting its strength, as the soft metal, by overcoming the friction, acts of the tube, and also that the drawing of the tube can be accomplished without injury to the soft metal or alloy, as a more even frictional action is created where it acts upon both the interior and exterior surfaces at the same time.

By the formation of the i, tween the soft metal and tain a tube which is not only highly polished on the interior andcxterior surfaces thereof, but substantially non-corrosive, having partaken of the nature of the soft-metal or alloy composite alloy bethe iron body I obsurface thereof, and which can be formed sufficiently light for use for pneumatic purposes and many of the uses for which brass or copper tubing has been heretofore almost exclusively employed, and which can be produced at considerable less 7 cost. The tube has also great advantages for boiler-fines and condensers, especially where the water contains any acid or alkali, as the metals so incorporated with the iron or steel tube will protect it from the action of acids, and the polished non-corrosive surface of the tube will prevent the formation of incrustation on the tube, so that oxidation becomes impossible, and the finished surface prevents the adhesion of any alkaline deposits.

What I claim as my invention, and desire to secure by Letters Patent, is

A new article of manufacture, consisting in a drawn-iron or'soft-steel tube having a soft metal or alloy compressed into and forming metal of the tube, on the interior andexterior surfaces thereof, substantially as and for the purposes set forth.

In testimony whereof I, the said EDMUND C. CONVERSE, have hereunto set my hand.

EDMUND C. CONVERSE.

I \Vitnesses:

JAMES l. KAY, Boer. D. TOTTEN.

to maintain the fibrous condition of the body a composite alloy with the molecules of the.

IIO 

